Robotic end effectors

ABSTRACT

An end effector suitable for use on a robotic arm associated therewith and coupled to a computer includes a universal mounting plate permitting the end effector to be mounted on the distal end of a robotic arm; a gripper mechanism slideably retained within the end effector is responsive to electronic command signals permitting the finger members disposed therein to acquire, lock and release, a plurality of tools and components upon receiving computer controlled electronic command signal. The electronic command signal controls the driving power from a power source which is coupled to the end effector.

The present patent application is a Continuation-In-Part Application ofpatent application Ser. No. 837,749, filed on Mar. 10, 1986, nowabandoned, which application is a Continuation application of parentapplication Ser. No. 580,715, filed on Feb. 16, 1984, which matured intoU.S. Pat. No. 4,591,198 on May 27, 1986.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to robotic end effectors, and moreparticularly, to a relatively small, lightweight, end effector having apair of hollow gripping fingers which are suitable for engaging,retaining and releasing a plurality of tools and components.

2. Discussion of the Relevant Art

The art abounds with end effectors utilized in combination with robotsto perform a plurality of operations in automatic production lines.Numerous types of end effectors, each designed for a specific function,are in use today. The automatic production lines require numerous robotseach performing their function in sequence so that the item beingmanufactured moves through numerous stations, each station adding acomponent or performing an operation on the article being manufactureduntil the article reaches the end of the production line where it isthen tested and packaged for shipment.

In order to improve the versatility of the end effectors numerousdesigns have been attempted which have as a design goal providing threedegrees of freedom to the end effector and robotic arm combinationpermitting manipulation similar to that accomplished by a human arm andhand. Typical of an end effector having force sensors in each fingertogether with a system providing three degrees of freedom force sensorson each finger utilizing strain gages to measure forces on the fingersas it contacts an article is disclosed in U.S. Pat. No. 4,132,318 issuedto S.S. Wang, et al on Jan. 2, 1979. The device disclosed therein iscapable of measuring the gripping force and a force vector applied tothe object being held by a manipulator finger of the end effector. Theend effector disclosed therein is computer controlled and utilizes thestrain gages and offset forces to direct the fingers of the end effectorto accomplish the desired goal. The type of functions that can beperformed with this type of end effector are limited.

In U.S. Pat. No. 3,905,632 issued to H. J. Caylor, et al on Sept. 16,1975 a gripping head apparatus is disclosed that is designed to beattached to the free end of a lifting boom structure which is configuredto grip, position, empty and release containers wherein the headcomprises a pair of movably mounted lifting arms arranged in opposedalignment in relation to one another. A rack and pinion arrangement isused to rotate the position of the container once it is picked up by theend effector. The device disclosed herein is utilized for the singularpurpose of raising a container, moving it to a new position and thentilting it so the contents thereof can be emptied. The apparatus isdesigned for use with relatively large containers and would beunsuitable for handling the manipulated of small devices or performingspecific functions on relatively small components.

Another mechanism utilized as an end effector on a robotic arm suitablefor gripping rigid products is disclosed in U.S. Pat. No. 3,655,232issued to G. A. Martelee on Apr. 11, 1972. The embodiment disclosedtherein utilizes a horizontal ram and from which are suspended hollowvertical telescoping grasping arms each housing a vertical cylindricalram connected to a compressed oil accumulator that supplies oil to thehorizontal ram and to a rotating ram about the vertical suspensionpivot. Here again, the device utilizes rack and pinion arrangementswhich are not suitable for the manipulative functions of which theinstant invention is capable.

The apparatus disclosed in the instant invention overcomes theshortcomings found in the prior art by providing an end effectorsuitable for use on the distal end of a robotic arm capable ofperforming numerous functions and is capable of engaging and releasingnumerous tool elements to aid in performing a plurality of functionswhile maintaining its small size and weight.

Therefore, it is the object of the present invention to provide arobotic end effector that is relatively small in size, reliable andsuitable for performing numerous functions.

It is yet another object of the present invention to provide a roboticend effector suitable for mounting on a plurality of robotic arms.

It is still yet another object of the present invention to provide arobotic end effector that is small in size and provides a relativelylarge gripper dimension.

It is still yet another object of the present invention to provide arobotic end effector that is capable of bi-directional linear motionsuitable for engaging the outer dimension of objects in addition to theinner dimension thereof.

It is still yet another object of the present invention to provide arobotic end effector suitable of engaging and exchanging numerous toolelements.

It is still yet another object of the present invention to provide arobotic end effector that is capable of automatically changing andreplacing tool elements and is capable of performing numerous functions.

It is still yet another object of the present invention to provide arobotic end effector capable of sensing when the object it is to engageis in the correct position for engagement thereof.

It is still yet another object of the present invention to provide asensing arrangement for the robotic end effector providing informationto the control computer for the robot that the end effector has notencountered an object in its path and/or has moved to a prescribedposition and is ready to perform it function.

SUMMARY OF THE INVENTION

An end effector suitable for use on a robotic arm coupled to a centralcomputer capable of providing an electronic command signal and a powersource, according to the principles of the present invention, comprisesin combination; attachment means for removably affixing the end effectorto the distal end of the robotic arm; a gripper apparatus which includesa pair of finger members having a hollow body portion slideably retainedwithin the end effector, the pair of finger members being adapted to becoupled, via a driving apparatus to a power source and cooperate withand removably retain and release a plurality of end effector tools andcomponents upon receiving an electronic command signal; each of saidfinger members is provided with a least one through aperture thatfunctions as an indexing means and a computer for generating the commandsignal, the command signal being coupled to the finger members forcontrolling the application of driving power from a power source.

The foregoing and other objects and advantages will appear from thedescription to follow. In the description reference is made to theaccompanying drawing which forms a part hereof, and on which is shown byway of illustration a specific embodiment in which the invention may bepracticed. The embodiment will be described in sufficient detail toenable those skilled in the art to practice the invention and it is tobe understood that other embodiments may be utilized and that structuralchanges may be made without departing from the scope of the invention.The following detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present invention is best definedby the appended claims.

BRIEF DESCRIPTION OF THE DRAWING

In order that the invention may be more fully understood, it will now bedescribed by way of example, with reference to the accompanying drawingin which:

FIG. 1 is a front view in elevation of a robotic end effector, accordingto the principles of the present invention;

FIG. 1A is a pictorial representation of a control computer coupled to arobot having a robotic arm with an end effector disposed on the distalend thereof;

FIG. 2 is an end view in elevation of the robotic end effector shown inFIG. 1 showing one indexing embodient;

FIG. 3 is an isometric view, partially broken away, of the robotic endeffector shown in FIG. 1;

FIG. 4 is a view in elevation, partially broken away, of the endeffector shown in FIG. 3;

FIG. 5 is a cross-section view in elevation of the end effector withportions broken away, in order to more clearly point out the features ofthe instant invention;

FIG. 6 is a partial top plan view of the pinion and rack geararrangement shown in FIG. 5;

FIG. 7 is a front view in elevation showing the engaging pins of atypical tool; and

FIG. 8 is a side view in elevation of the tool shown in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the figures, and in particular, to FIGS. 1 and 2, thereis shown a front view in elevation and a side view in elevation of anend effector 10, according to the principles of the present invention.The upper portion 12 of the housing 14 of the end effector 10 isprovided with a reinforced portion 16 that is provided with threadedapertures 18, 20, 22, and 24 therein which are adapted to receivethreaded bolts 26, 28, 30 and 32 used to affix a universal mountingplate 34 to the reinforced portion 16 of the end effector 20. Theuniversal mounting plate 34 is provided with through apertures 36, 38,40 and 42 which are adapted to cooperate with and receive bolts 26, 28,30 and 32 to enable universal mounting plate 34 to be mounted on endeffector 10. Through apertures 44, 46, 48 and 50 provided in universalmounting plate 34 permit the end effector 10 to be affixed to the distalend 159 of different types of robotic arms 163 such, as for example,bolts 26, 28, 30 and 32. Thus, by providing proper mounting holes in theuniversal plate 34 the end effector 10 may be affixed to known roboticarms or by changing plate 34 the mounting holes can be configured to anydesired application.

The end effector 10 is provided with a pair of hollow gripped fingers 52and 54 that extend outwardly from the hollow housing 14. The hollowhousing 14 is generally U-shaped and open on the bottom so that thegripper fingers may freely move in the direction of arrows 56 and 58.Each of the gripper fingers 52 and 54 move linearly inwardly andoutwardly (bi-directionally) simultaneously, as will be explainedhereinafter.

The open front and rear portions of the housing 14 are provided withcovers 60 and 62 which are fastened to the housing by means of screws64, 66, 68 and 70, in a conventional manner. The upper portion ofhousing 14 may also include indicator lights 72, 74 and 76, which may beused to indicate that the light emitting device 78 disposed within thedistal end of hollow gripper finger 52 which provides an infra-red lightbeam 80 that is received by the photoelectric detector 82 disposed inthe hollow distal end of gripper finger 54, has been interrupted by anobject being interposed therebetween. In addition to illuminating lamp72 an electronic signal may be sent to the main computer 161 that theobject to be captured is in position so that the computer may initiatethe proper signal to perform the next function of the end effector (e.g.close fingers 52 and 54). Indicator light 74 may be utilized to indicatewhen a tool has been engaged and is in position as well as provide thenecessary signal to the main computer to initiate the next function. Ina similar manner, indicator light 76 is illuminated to indicate that thecomponent part has been capture by the tool as will be explainedhereinafter, also providing information to the main computer that theend effector 10 is available for its succeeding function.

Preferably, the finger grippers 52 and 54 are covered with resilientboot members 84 and 86 that are provided with a plurality of protrusions88 and 90, respectively, that increase the surface friction so that thefingers may more readily grip and retain a component or article which itattempts to capture. Apertures 92 and 94 are provided in the boot member84 and 86, respectively, to prevent interference with the infra-red raysemanating from the light emitting device 78 to the photoelectricdetector 82. Gripper fingers 54 and 52 are each provided with alignmentmeans or indexing, which comprise elongated through apertures 96, 98,100 and 102 proximate the distal end thereof, the function of which willbecome apparent in the description which follows.

Referring now to FIG. 3, which is an isometric views partially brokenaway, of the embodiment disclosed in FIGS. 1 and 2. The generallyU-shaped housing 14, with its upper portion 12 being closed (inverted U)has a centrally, longitudinally disposed shaft 104 which, when shown incross-section, resembles an I-beam with the lower portion 106 thereofbeing slightly larger in size than the upper portion 108. Shaft 104 isheld in position by screws 110 and 112 in one arm portion 118 (FIG. 1)of the housing 14 while the other end is held in position by screws 114and 116 inserted through apertures provided in the other are portion 120of housing 14 (see FIGS. 1, 2, 3 and 4). Preferably, shaft 104 iscentrally disposed in the housing 14 and also provides structuralreinforcement. Centrally disposed in the shaft 104 is a pinion gear 122which has its axis perpendicular to the axis of shaft 104 and rotates ina plane parallel to the upper and lower portions 106 and 108 of I-beam104. Pinion gear 122 may be installed with a free wheeling bushing 123in order to provide minimum frictional losses during rotation thereof.The upper portion 124 of gripper finger 54 is disposed transverse to theaxis of shaft 104 and has two apertures 126 and 128 provided proximatethe outwardly extending arms thereof into which are mounted circulatingball bushings 130 and 132. Ball bushings such as that manufactured bythe Heim Corporation of the State of Connecticut, Model number 887X250SS are adapted to receive guide shafts 134 and 136 therein,respectively. Thus, gripper finger 54 may freely slide along and beguided by shafts 134 and 136.

Extending upwardly from the transverse upper portion 124 is a shelfportion 138 upon which a pneumatic double acting cylinder 140 is mountedby means of two pairs of screws 142 and 144 that engage the housingportion 146 of the cylinder 140 thereby affixing the housing of thecylinder with respect to finger 54. A typical cylinder suitable for thisapplication is manufactured by Compact Air Products of Westminster, S.C., Model No. BD118X2-EXD12118. The cylinder 140, being of the doubleacting type is provided with a centrally disposed rod 148 which extendsoutwardly from either end of the cylinder and is provided with a centralbore on both ends adapted to receive screws 150 and 152 (FIG. 1), whichextend through the arm portions 118 and 120 (FIG. 4) of the housing 14thereby affixing the rod with respect thereto. Thus, it can be seen thatby activation of the double acting cylinder 140, the housing 146 thereofcan be moved from one end to the other of the rod while the rod remainsstationary. Activation or movement of the housing 146 is accomplished bythe application of a fluid under pressure, e.g., compressed air,entering, via input nozzle 154 or 156. Input nozzles 154 and 156 arecoupled, via a flexible hose 158 and 160, respectively, to a source ofcompressed air, not shown, the direction of which is electronicallycontrolled by a signal from the central computer 161 coupled to therobot 163, via cabling 165 shown in FIG. 1A.

The shelf portion 138 of gripper finger 54 is additionally provided withan upwardly extending portion 162 which is provide with an aperture 164into which is mounted a circulating ball bushing 166 adapted to receivea guide shaft 168 therein which is affixed to the arm portions 118 and120 of housing 14 by means of two screws 170 and 172 in a manner similarto that utilized for guide shafts 134 and 136.

A rack gear 174, shown most clearly in FIGS. 4 and 5 is in cooperativecontact with pinion gear 122 and is affixed to upwardly extendingportion 162 beneath the shelf portion 138 of gripper finger 54 by meansof five (5) screws 176, 178, 180, 182 and 184, as is best shown in FIGS.4, 5 and 6. Screws 176, 180 and 184 are of the shoulder type and arethreaded into rack 174 and are inserted through a clearance hole 185(see FIG. 6). Screws 178 and 182 are set screws which are threaded intoaperture 188 provided in the upwardly extending portion 162 of gripperfinger 54. Set screw 178 may be provided with a resilient tip, such asnylon. By utilizing the shoulder screws together with the set screws ablind alignment may be accomplished and rack 174 may be aligned tocooperate with and be in intimate contact with pinion gear 122 with aminimum of resistance forces. Shoulder screw 176, when rotated, iscapable of moving the rack away from the pinion gear 122 while set screw188 may move the rack 174 closer to the pinion gear. By carefuladjustment, one is able to align the rack in a position which isparallel to the axis of pinion gear 122 providing free movementtherebetween. Thus, by providing movement to rack 174 rotation of piniongear 122 occurs transferring the radial movement to linear movement inrack 186 which is connected in the identical manner to upwardlyextending portion 188 provided on gripper finger 52. By the arrangementset forth herein it becomes obvious, that if rack 174 is to move oneinch in the direction of arrow 190 (see FIG. 6) the movement will becoupled, via pinion gear 122 causing rack 186 to move in the directionof arrow 192 an equal amount in the opposite direction. Thus, drivingrack 174 which is attached to gripper finger 54 by moving one inch in anoutwardly direction will cause gripper fingers 52 to move an equaldistance in the opposite direction, thereby making the total distancebetween the gripper fingers 52 and 54 equal to two inches.

Rack 186 is connected to upwardly extending portion 188 of gripperfinger 52 with the aid of five (5) screws 194, 196, 198, 200 and 202.Preferably, screws 194, 198 and 202 are shoulder screws with screws 196and 200 being set screws, all of which function in the identical mannerto screws 176, 178, 180, 182 and 184 and control the alignment of rack186. Shoulder screws 194, 198 and 202 are provided with clearanceapertures in the upwardly extending portion 188 while set screws 196 and200 are provided with threaded apertures in the upwardly extendingportion 188 thereby providing identical means for alignment withoutbeing able to see the cooperating portions of the rack and pinion gears.

In lieu of a shelf portion, the upwardly extending portion 188 ofgripper finger 52 is provided with an upright portion 204 which isprovided with an aperture 206 into which is mounted a circulating ballbushing 208 that is adapted to receive a guide shaft 210 therein. Guideshaft 210 extends from one arm 118 of the housing 14 to the other end120 of the housing 14 and is affixed therein by means of grooves in theidentical manner as guide shaft 168. The transverse upper portion 212 ofgripper finger 52 is also provided with an aperture into which ismounted a circulating ball bushing 214 thereby permitting gripper finger52 to move freely along the guide shafts 210 and 134 in a manner similarto that of gripper finger 54 except that movement occurs in the oppositedirection as explained earlier. Motion between gripper fingers 52 and 54is linear in nature and bi-directional.

By comparing the location of the components as disclosed in FIGS. 3 and4, it can be seen that gripper fingers 52 and 54 extend downwardly outof the housing 12 and are permitted unrestricted movement with gripperfinger 54 being the driven element and gripper finger 52 being the slaveelement.

Referring now to FIG. 5, there is shown in cross-section gripper finger54 which is generally hollow in nature being provided with an elongatedhollow or channel 216 into which is mounted a super-slim cylinder 218with a rectangular cross-section of the type manufactured by FestoIndustries of Hauppauge, N.Y. Model No. 9505EZH2, 5/9-10. A cylinder 218or, alternatively, an electrical solenoid is mounted in the hollow 216with the aid of two (2) screws 220 and 222 and is provided with arectangularly-shaped piston rod 224 and is biased by a spring 225, toits normal rest position shown in FIG. 5. Transverse pins 226 and 228,preferably roll pins, are positioned in a normal rest position to beproximate apertures 96, 98, 100 and 102. Thus, when cylinder 218 isactivated (supplied with compressed air into the input nozzle 230 whichis coupled, via a flexible hose 232 to the source of compressed air) bya control signal from the computer 161, the piston rod 224 will causepins 226 and 228 to extend into the area of the tool alignment orindexing apertures 96, 98, 100 and 102. Thus, anything inserted intothese indexing apertures such as tool indexing protrusions (see FIGS. 7and 8) would be restrained therein by the force generated by theactivating air.

FIGS. 7 and 8 disclose a front and side view, respectively, of a typicalend effector tool 234 that may be used in conjunction with the gripperfingers 52 and 54, if it is desired to pickup a circularly-shaped objectfor example. As shown in the figures the end effector tool 234 includesoutwardly extending protrusions 236, 238, 240 and 242 which aregenerally rectangularly-shaped in cross-section and are provided withthe grooves 244, 246, 248 and 250, respectively, in each of theprotrusions. The protrusions are selected to mate in only one way withthe apertures 96, 98, 100 and 102 provided in the gripper fingers 52 and54 to provide indexing (alignment) and are capable of being inserted onthe outwardly extending surface or the inwardly extending surface of thegripper fingers. Once inserted in the apertures, activation of thecylinder 218 causes piston rod 224 to move into V-grooves 244, 246, 248and 250 causing the end effector tool 234 to be locked into position.This is accomplished by a signal from a master control computer 161causing the cylinder 218 to be activated at the appropriate time. Thetool 234 is, therefore, locked in place until fluid pressure is removedfrom cylinder 218. The V-grooves provide almost perfect alignment andmaintain the integrity and accuracy of the gripper fingers 52 and 54. Itis to be noted that although a typical tool is shown herein, any numberof tools may be utilized together with gripper fingers 52 and 54.

Typical end effector tools, of various types, are disclosed in U.S. Pat.No. 4,781,519 issued to Mathew L Monforte on Nov. 1, 1988 and U.S. Pat.No. 4,627,785 issued to Mathew L. Monforte on Dec. 9, 1986 and disclosethe various end effector tools that may be utilized in an automaticproduction line wherein the subject robotic end effector may be used.

In operation, the robotic end effector 10 receives compressed fluid,preferably air, from a fluid source under pressure. The airflow iscontrolled by the master computer and an electronic signal dictateswhich of the input nozzles 154 or 156 is to receive the compressedfluid. Thus, the directional movement of gripper fingers 52 and 54 isdetermined with fluid under pressure being applied to one nozzle tocause movement of the gripper fingers in an inwardly direction, toacquire a tool, while compressed fluid being applied to the other nozzlecauses the gripper fingers to move in an outwardly direction in order toacquire a different tool. Locking or releasing various end effectortools is accomplished after the robotic arm moves the end effector to aprescribed location wherein the gripper fingers are caused to acquirevarious and different end effector tools located in specificcoordinates. Once the tools have been located and engaged in aparticular manner by the indexing (alignment) arrangement, energizingpiston 218 by means of a signal from the central computer 161 will lockthe tool in position wherein the robotic arm then moves it to performany number of functions.

The end effector tool disclosed herein utilizes a base portion 252having an alignment or indexing arrangement which includes members 244,246, 248 and 250 that is adapted to cooperate with apertures 96, 98, 100or 102 provided on the end effector fingers 52 or 54, and a resilientportion 254 which is provided with a curved outer surface 256 ideallysuited to engage a round object. By utilizing the infra-red light source78 together with the photoelectric detector 82 the central computer canbe notified when the object to be engaged interrupts the light beamoccurring between gripper fingers 52 and 54. Thus, the computer canindicate and instruct the gripper fingers to close and engage the objectas required, and once retained, the computer can move the robotic arm toits required position, in a conventional manner.

Hereinbefore has been disclosed a relatively simple end effector whichis reliable, small in size, having a relatively large gripping dimensionfor its size and is ideally suitable for use on a plurality of roboticarms. It will be understood that various changes in the details,materials, arrangement of parts and operating conditions which have beenherein described and illustrated in order to explain the nature of theinvention may be made by those skilled in the art within the principlesand scope of the instant invention.

Having thus set forth the nature of the invention, what is claimedis:
 1. An end effector suitable for use on a robotic arm coupled to acentral computer capable of providing an electronic command signal and apower source associated therewith, comprising, in combination:(a) meansfor removably affixing said end effector to the distal end of saidrobotic arm; (b) gripper means including;(i) a pair of finger membershaving a hollow body portion slideably retained within said endeffector, said pair of finger members being adapted to be coupled, via adriving means to said power source and cooperate with and removablyretain a plurality of end effector tools and components, each of saidfinger members being provided with at least one through aperture thatfunctions as an indexing means, and (ii) first means disposed entirelywithin each of said hollow body portions of said finger members forlocking and releasing said tools and components having cooperatingprotrusions extending into said through aperture upon receiving saidelectronic command signal; and (c) second means for couplinq saidelectronic command signal to said pair of finger members and forcontrolling the application of power from said power source.
 2. Arobotic end effector according to claim 1, further including sensingmeans disposed within and proximate the outwardly extending distal endof said gripper means finger members for sensing the location of anobject being acquired by said gripper means finger members.
 3. A roboticend effector according to claim 1, wherein each of said finger membershas one end thereof coupled to said driving means operatively coupled tosaid power source, for providing linear bi-directional displacement ofsaid finger members.
 4. A robotic end effector according to claim 3,wherein said through aperture of each of said finger members hollow bodyportion is disposed proximate the distal end thereof, said first meansincluding piston means disposed within each of said finger membershollow body portion, said piston means having a movable rod membercapable of movement proximate said through aperture sufficient tocapture a protrusion placed in said through aperture, and means foractivating said piston means to capture said protrusion placed in eachof said finger members hollow body portion through aperture.
 5. Arobotic end effector according to claim 3, wherein said driving meanscomprises a body member and a slideable rod member disposed therein,said slideable rod member being movable in both directions relative tosaid body member, said one end of one of said pair of finger membersbeing affixed to said body member, means for operatively coupling saidone end of the other of said pair of finger members to said rod member,thereby providing bi-directional linear motion between said pair offinger members.
 6. A robotic end effector according to claim 5, whereinsaid means for operatively coupling said one end of the other of saidpair of finger members to said rod member comprises:(a) a housingmember, having a centrally disposed longitudinal shaft disposed therein,said shaft having a centrally disposed pinion gear disposed therein withits axis of rotation perpendicular to said shaft; (b) first rack gearmeans, said body member being affixed to said first rack gear means,said first rack gear means slideably affixed in said housing member andoperatively coupled to and cooperating with said pinion gear; (c) secondrack gear means, said one end of the other of said pair of fingermembers being affixed to said second rack gear means, said second rackgear means being slideably affixed in said housing member andoperatively coupled to and cooperating with said pinion gear on theopposite side thereof, so that movement in one direction of said firstrack gear means will cause movement in the opposite direction of saidsecond rack gear means.
 7. A robotic end effector according to claim 6,further including first and second. guide rail means disposed in saidhousing member parallel to said longitudinal shaft, said first guiderail means being slideably connected to one of said finger membersproximate said one end of said pair of finger members to direct themovement of one of said finger members, said second guide rail meansbeing disposed in said housing member parallel to said longitudinalshaft, said second guide rail means being slideably connected to theother of said finger members proximate said one end of said pair offinger members to direct the movement of the other of said fingermembers.
 8. A robotic end effector according to claim 7, wherein saidfirst and second rack gear means includes a rack gear and screwadjustment means, said screw adjustment means affixing said rack gear tosaid one end of each of said pair of finger members for permittingadjustment to obtain alignment with said pinion gear.
 9. A robotic endeffector according to claim 6, wherein said centrally disposedlongitudinal shaft in cross-section comprises an I-beam.
 10. An endeffector suitable for use on a robotic arm associated therewith;comprising in combination:(a) means for removably affixing said endeffector to said robotic arm, said affixing means including;(i) auniversal mounting plate, (ii) a plurality of apertures disposed in saidplate adapted to cooperate with apertures provided on a plurality ofrobotic arms, and (iii) means for connecting said universal mountingplate to said robotic arms; (b) gripper means, slideably retained withinsaid end effector, adapted to be coupled to a power source and to acentral computer capable of providing an electronic command signal, saidgripper means cooperating with and removably retaining a plurality ofend effector tools and components upon receiving said electronic commandsignal, said gripper means including;(i) a pair of finger members havinga hollow portion, one end of said finger members being affixed to adriving means operatively coupled to said power source for providinglinear, bi-directional displacement of said finger members, the otherend of said finger members extending outwardly and including entirelywithin said hollow portion means for locking and releasing end effectortools and components responsive to said command signal; and (c) meansfor coupling said electronic command signal to said locking andreleasing means for controlling the application of power from said powersource.
 11. An end effector suitable for use on a robotic arm coupled toa central computer capable of providing an electronic command signal andadapted to be connected to a power source, comprising, incombination:(a) means for removably affixing said end effector to thedistal end of said robotic arm; and (b) gripper means including a pairof hollow finger members slideably retained within said end effector,each of said finger members including;(i) aperture means for mating withand removably retaining a plurality of end effector tools and componentshaving protruding means for extending into said aperture means, and (ii)means disposed entirely within each of said hollow finger members, forlocking and releasing said end effector tools and components from eachof said finger members responsive to said electronic command signal.